I was wonder what i can do to help my wife to get her little sister to move her in the us.

See an attorney to discuss options for sis.

I have applied for removel of my conditional residency in 2-15-2012 yet still have not recived my new ten year green card ?

This is tricky. They have to give you a final approval on. The 10 year card before you can be approved for naturalization but if you timely file...

Is it neccesary'to hire an attorney to file for the Deffered Action?

Not necessary but recommended.

Change of status from h1 to f1? Is it ok if i apply for change of status just few days before i stop working?

Yes. File before the H expires and you will remain in a pending status.

No pp but speak to your DSO.

I am on H4 visa with 1 yr old baby. My husband has been abusive and is now living separately. What if he files divorce?

Unfortunately you are on the verge of many problems. If he files for divorce you are still in H status but when the divorce is final you loose the...

Is it B1/B2 visa OK if my employer (from Europe) had long term contract with US Company and I am visiting US as a subcontractor.

The visa is fine, but you must enter as a B-1 and not a B-2.

Yes, these are sections of law that your husband violated somehow. See an attorney for waivers and the possibility of him coming back.

Should we remarry and refile or should my ex husband wait for I 360?

This is too complicated for this forum. You really need some solid advice after an attorney has talked to about all issues.

Is I-140 approval prior to I-485 in case of EB1-C for someone who is already under L1. What processing time should i expect?

Six to eight months is standard time. Your leave of absence should be ok as long as you have a good reason fir it if they ask you.